NEMA published ANSI C18.1M, Part 1 American National Standard for Portable Primary Cells and Batteries with Aqueous Electrolyte—General and Specifications. Revision was developed to ensure electrical and physical interchangeability for most primary batteries—carbon zinc, alkaline manganese dioxide, silver oxide, zinc air, and nickel oxyhydroxide. Test schemes for 13 D, 14 C, 15 AA, and 24 AA batteries have been modified along with application test updates for 7000 series of hearing-aid batteries.